This invention relates to a system for rapidly cooling very hot exhaust nozzle surfaces of gas turbine engines, and is particularly useful in connection with gas turbine engines where very rapid cooling may be desirable or essential.
Traditionally, engine bypass air is the primary source for cooling of the exhaust nozzle of gas turbine engines and there are many patents showing various arrangements for such cooling. For example, U.S. Pat. No. 4,833,831 shows a gas turbine augmentator having a film cooled liner provided with fan bypass air. Other patents showing similar systems include U.S. Pat. Nos. 4,813,229, 4,800,718, 4,544,098, 4,817,378, 4,081,137 and 4,203,286. All of the foregoing prior art patents show various arrangements for providing cooling air to the exhaust nozzle, but none utilizes the total engine air flow. Each of these systems uses fan bypass air to which a considerable amount of heat has been added as the air passes through the engine.